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inauspicious temperature. If these could be all 

 avoided, a plant might enjoy a vigorous immortality. 

 Such, however, is not the lot of any organized being, 

 and in proportion to the debilitating circumstances, 

 are the nature, the intensity, and final consequences 

 of the disease induced. The apple-tree is liable to 

 distempers arising from each of those causes, and its 

 distempers, owing to its value as a fruit-bearer, have 

 been more watched and discussed than those of any 

 other plant. The results from those discussions are 

 not very luminous, nor does this afford a subject for 

 surprise, vegetable nosology being one of the most 

 obscure paths in the whole region of human knowledge. 



Canker is the most common and the very worst 

 disease to which the apple is liable. To what cause 

 this is attributable is at present uncertain, or whether 

 to a combination of causes. "\Ye have always noticed 

 one thing, and that is, that severe disrootings or root 

 cutting, seems at least to lessen its virulence. From 

 this we are led to think, that immature wood, trans- 

 ferred from stock to stock, has a strong tendency to 

 produce it. It is not improbable, too, that the indivi- 

 dual character of the stock has something to do in the 

 affair ; for we have an instance under our eyes of a 

 fact or two, which rather tend to give such an impres- 

 sion. In 1832 we found the Hawthornden cankering 

 so badly — not one tree, but all — that we destroyed the 

 stock, reserving, however, a healthy graft or two ; 



